Injector



2 Sheets-Sheet: l

J. F. GRIFFIN INJECTOR Filed March 7, 1954 Oct. 6, 1936.

(/OfF/fi 9" ATTORNEY INVENTOR J. F. GRIFFIN Oct. 6, 1936.

INJECTOR Filed March '7, 1954 2 Sheets-Sheet 2 INVENTQR /wp a F6 fi ATTORNEY Patented Oct. 6, 1936 UNITED STATES PATENT OFFICE INJECTOR Joseph F. Griffin, Teaneek, N. J., assignor to The Superheater Company, New York, N. Y.

The present invention relates to injectors and has particular reference to exhaust steam injectors. Still more particularly the invention relates to exhaust steam injectors for steam locomotives.

Exhaust steam injectors, as commonly applied to locomotives, are ordinarily mounted, for practical considerations, at some place on the locomotive outside of the locomotive cab, and in most instances at a place on the locomotive where it is difficult, if not impossible, to see the injector from within the cab of the locomotive. The most usual location for such injectors is at a low level on the locomotive beneath the cab. Because of the practical necessity of locating the injector outside of the cab, remote control systems for such injectors have been developed whereby it is possible for the injector operator to control the operation of the injector from within the cab.

Due to the wide variations in the conditions under which locomotive injectors must operate, their proper working may be and frequently is interrupted and means have heretofore been proposed for warning the operator of unstable operation of the injector whereby the operator may be enabled to readjust the injector control so as to insure continued stable operation. When the injector ceases to operate properly and also prior to the establishment of the injector jet when the injector is started, the injector overflows through the usual overflow passage, and. this overflow of the injector is in practice largely relied upon by the injector operator as a means for definitely ascertaining whether or not the injector is operating properly.

In usual locomotive installations, the operator cannot see the injector overflow from a position within the locomotive cab, and it is common practice for such operators to lean out of the cab to observe whether or not the injector is overflowing. This practice is extremely dangerous, and in order to avoid the necessity for such practice it has heretofore been proposed to utilize the pressure existing in the overflow chamber of the injector, which pressure is indicative of the stability of operation of the injector, to actuate some form of visual signal within the cab, by means of which the operator has an indication as to whether or not the injector may require regulation. One typical form of such apparatus is a pressure gauge located in the cab connected to the overflow chamber of the injector. When the hand of the gauge moves through a red sector on the gauge dial it indicates either that the tor to lean out of the cab window to see that the 1 injector is actually spilling. The reason that the gauge in the cab cannot positively indicate whether or not the injector is spilling is because spilling does not always occur at the same overflow pressure. It varies mainly in relation to the delivery pressure, but also with suction water temperatures and other variables present in normal locomotive operation. The gauge indicator can, at best, provide only an approximate indication, and one of the most dangerous conditions which has been found in practice to exist when gauge indication is relied upon, is that the injector may break and allow steam to blow back into the suction line, while the gauge indicator in the cab indicates an overflow pressure indicative of stable operation. When this occurs, the first intimation that the operator has that the injector is not feeding water to the boiler is when the water level in the boiler falls. Thus, when the condition is discovered and it is attempted to regulate the injector to secure proper operation, difliculty is often encountered in starting the injector because of the hot suction water which has become heated by the blowing back of steam to the suction line.

It is a general object of the present invention to provide a positive indication, at a place remote from the injector, which is of course advantageously at the place of control of the injector, that the injector is in an unstable range approaching the condition which will result in failure of operation, and which will also provide positive indication of failure of the injector to operate when steam and water are being supplied thereto.

The more specific nature of the invention, together with the more detailed objects thereof, will become apparent in conjunction with the ensuing description.

In order to better understand the nature and application of the invention we shall first state the characteristics of operation of injectors of the character under discussion.

When operation is commenced by the admission of steam and water to the injector, a certain amount of water is discharged through the overflow passage of the injector until the jet is established and delivery commences. At this time, assuming that the injector is operating within its normal capacity range, overflow ceases. During normal operation of an injector the pressure in the overflow chamber may be below atmospheric and consequently an overflow valve is provided in order to prevent ingress of air through the overflow opening. In some types of exhaust steam injectors it has been found that the injector will operate satisfactorily with a pressure above that of atmospheric in the overflow chamber and con-' sequently such injectors are usually provided with overflow valves which are loaded when the injector is in operation. Usually the-load on the 1 overflow valve is provided by pressure taken from Y the delivery of the injector, since this pressure is available whenever the injector is in operation and is automatically released when theinjector' is. not in operation. so thatv the overflow valve willbe. unloaded to. permit free overflow at the time the injector is started. When an injector with loaded overflow is operating in its most stable range, -the overflow chamber is at sub-atmospheric pressure, and whenthe change of some variable affecting stability of operation occurs to render the. operation less stable, the pressure in the. overflow chamber rises. For example, if the supply of water to the injector is cut down to a valueapproaching the minimum of the ca-- pacity range or the. injector, pressure rises in the overflow chamber until. finally a pointis reached where this pressure opens the overflow valve 1 against the loading pressure and the injector overflows- This type of overflow is usually followedby what iscalledbreaking, meaning a complete. failure of the jet when a portion of the steam supplied. to the injector blows out the overflow and the remainder blows back through the suction-line. If, on; the other hand, the supply of water to the injector is increased to a value approaching the upper capacity limit of the injector, the pressure in the overflow chamber rises due to thefact the quantity of water is approaching the point whereinsuflicient steamis available for forcing. the water through the injector, and the overflow valve may be lifted to some extent to: permit. excess water to overflow from the injector. This type of overflow can occur without interruption of the injector operation, but in additionr to the undesirable loss of water, this condition of operation is so unstable that complete breaking of operation of the injector, with the consequent highly undesirable blowing back of the steam into the suction line,.is imminent.

I have found that when an injector of the character under discussion approaches capacity operation, by which term I mean operation approaching thecapacity of the injector to operate under any givenrset of conditions, the rise in pressure inrthe'oyerflow chamber is accompanied by a spill from the jet which enters the overflow chamber through the usual gap'between the combining and delivery tubes of the injector, and which spill flowsfrom theoverflowchamber past the overflow valve while the latter is substantially seated: The character of this relatively small spill may be likened to the leakage which would occur between the flanges of aflanged joint under pressureif the bolts holding the flanges together were slightly loosened. This-spill takes place-without interrupting the continuedoperation of the inicctor, but I'have found that operation of the iniector under the-.conditions producing. such a spill is dependent upon the continuance of such spill. In other words, if the injector is operating with this type of spill taking place and additional load is placed on the overflow valve so as to stop this spill, it will result in immediate cessation of operation or breaking of the injector.

In accordance with the present invention, I propose to utilize this spill, which occurs at near capacity operation of the injector, regardless of the absolute pressure which may exist in the overflow chamber at the time, to provide-a positive and substantially infallible indication of the condition of injector operation. Preferably, I utilize thischaracteristic to provide the desired signal by conducting the spill to or adjacent the place of control of the injector to provide a visual signal readily discernibleby the injector operator. The

I specificmeans by which such spill may be utilized to provide the desired indication may take many different forms, and for purposes of illustration I have shown in the accompanying drawings several embodiments of apparatus suitablefor carrying the invention into effect.

In the drawings:

Fig. 1 is a side elevation of part of a locomotive showing exhaust steam injector apparatus embodying the invention;

Fig. 2 is a section on an enlarged scale of part of the injector shown in Fig. 1 taken on the line 2-2 of Fig. 1;

Fig; 3 is a section taken on the line 3-3' of Fig. 2;

Fig. 4 is a section similar to Fig. 3 showing another form of overflow valve arrangement;

Fig.5 is a section showing a variation of the form of valve shown in Fig. 4;

Fig. 6 is a section showing still another form of overflow valve arrangement; and

Fig. 7 is a View showing still another arrangement of apparatus embodying the invention Referring to Fig. 1, reference numeral I!) indicates the boiler of a locomotive at the rear end of the whichis located the cab l2. Located beneath the cab is an exhaust steam injector indicated generally at A, which, for purposes of illustration, is indicated as being of the kind shown and described in U. S. Pat. No. 1,870,006 granted August 2, 1932 to Malcolm Hard, to which reference may be had for details of construction.

It will be understood that the present inventionis applicable to other types and kinds of injectors including live steam injectors. In the injector illustrated, exhaust steam is supplied to the injector from the exhaust passages of the locomotive cylinders through pipe I6. Live steam for operating the injector in conjunctionv with exhaust steam and also for operating the injector as a live steam injector when exhaust steam is not available is supplied from the boiler turret l8 through the live steam supply pipe 20. Flow of steam through pipe 20 is controlled by the remote control valve 22 located in a convenient position in the cab of the locomotive. Water is supplied to the injector from the locomotive tender (not shown) through the suction pipe 24, and the amount of water supplied to the injector is controlled by means of the operating handle 26 also located in the locomotive cab. The injector illustrated is shown as having an automatic control system of known kind for automatically shifting the injector from live steam operation to exhaust steam operation and vice versa depending upon the presence or absence of exhaust steam. This control system which comprises, among other elements, a diaphragm valve 28 in communication with the exhaust pipe It by way of pipe 30 and a changeover valve 32 controlled by valve 28, is not per se a part of the present invention, and is fully described in the Hard patent above referred to. Insofar as the present invention is concerned, automatic control systems of this character may be omitted or other types of control systems may be employed.

Overflow from the injector is carried to any suitable place of discharge through the overflow pipe 34 and the overflow valve of the injector may be positively closed by the injector operator through the medium of the control handle or Wheel 35 located in the cab of the locomotive.

Turning now to Figs. 2 and 3, the portion of the injector with which the present invention is concerned comprises a casing 38 in which are located the usual combining and delivery tubes 40 and 42 respectively. Between tubes 40 and 42 there is located a gap 44 which is in communication with the overflow chamber 46. Tube 42 discharges into a delivery chamber 48 separated from the overflow chamber 46 by the collar 50 on the delivery tube 42, which collar also serves as a means for mounting the delivery tube. The overflow chamber 46 is in communication by way of passage 52 with the overflow pipe 34 and communication between the outlet of chamber 46 and passage 52 is controlled by the overflow valve means which in the present embodiment comprises two separate valve heads 54 and 56. Valve head 54, which may be termed a primary valve, engages seat 58 to close the outlet of the overflow chamber 46, and the valve head 56, which may be termed a secondary valve, engages seat 60 to provide a space or chamber 62 between the two valve heads. Valve head 54 is provided with an upwardly projecting stem 64 terminating in a head 66 adapted to be contacted by the free end of a lever 68 pivoted at 10 on the injector casing. The opposite end of lever 68 passes through an aperture in the upper end of a plunger 12, which extends through a suitable packing gland M on the injector casing. The inner end of plunger 12 is located in the delivery chamber 48 of the injector. A threaded stud i6, mounted in a suitable bracket flxed to the injector casing, is adapted to be screwed down by manipulation of the overflow control 36 so as to force the free end of lever 68 downwardly to positively seat the valve head 54. Valve head 55 has an upwardly projecting annular stem 18 between which and the head 66 of the stem 64 is located the spring 813. A pipe 82 in communication with chamber 62 leads from the injector to the cab of the locomotive and terminates in an open end 84 preferably located where it will be prominently in view of the injector operator. Below and spaced from the open end 84 of pipe 82 there is located a cup or funnel shaped drain 86, from which a drain pipe 88 leads to any suitable place of discharge.

The operation of the above described apparatus is as follows: Assuming the injector is not in operation it will be evident that no pressure will exist in the delivery chamber of the injector and consequently the delivery valve means will have no pressure load thereon. If now, water and steam are admitted to the injector the normal overflow from the injector prior to establishment of the jet will open the overflow valve means and overflow through pipe 34 will take place. Upon establishment of the jet the overflow will cease and delivery pressure acting on the plunger 12 will cause lever 68 to seat the valve head 54.

Spring 80, with the valve head 54 seated, will also seat the valve head 56. As long as the injector operates in a stable range of operation, even though the pressure in the overflow chamber 45 is above atmospheric, the delivery pressure acting on plunger 12 will serve to keep the valve head 54 tightly seated so that no leakage will occur from chamber 46 to chamber 62. If now the injector approaches capacity operation and enters an undesirably unstable range of operation, the spill accompanying this kind of operation will commence and valve head 54 will be lifted against delivery pressure sufliciently to permit this spill to escape from the overflow chamber. The amount of lift of the valve head 54 from its seat under these conditions will be negligible and spring 30 will continue to maintain valve head 56 in seated position. Thus the spill will flow from chamber 45 to chamber 62 and since the spring continues to maintain valve head 56 seated the spill will flow from chamber 62 through pipe 82 to provide at the outlet 84 in the cab a positive indication that, regardless of the particular combination of conditions existing at the moment, the injector is operating in an unstable range and breaking of the injector is likely to occur. If the warning given by this indication is not heeded and the injector controls adjusted, and as a consequence the injector jet breaks, the failure of delivery pressure will immediately permit the overflow valve head 54 to open, together with valve head 56, so as to permit free overflow to pipe 34. With both valve heads in open position, the amount of overflow occurring at the time, and also during the normal starting overflow period, is such that suflicient pressure will exist at the inlet of pipe 82 to cause some flow upwardly through this pipe to the outlet 84, thus avoiding the possibility of the injector operator not being apprised of the fact that the injector is overflowing after the injector has ceased to operate. In order to insure ready starting of the injector it is necessary that a comparatively free flow to the overflow 34 be provided, but the amount of restriction in the flow passage necessary to cause a part of the overflow to be forced up through pipe 82 when the overflow valve means is opened is negligible, since the pressure required to lift the overflow from the injector to the cab is very little.

The manual control means for positively closing the overflow valve is not intended to be used during normal operation of the injector out is intended for use only for certain purposes such, for example, as to blow steam back through the suction line to clear it or the suction strainer of obstructions and also to prevent the escape of steam which may be admitted to the injector to prevent freezing.

In Fig. 4 there is illustrated another form of overflow valve means in which the outlet of the overflow chamber 46 is controlled by a singleoverflow valve head 90 adapted to engage a plane annular seat 92 and having a downwardly extending peripheral flange 94 adapted to slide with respect to a cylindrical surface 95 spaced from the seat 92 to provide a chamber 98 corresponding to the chamber 62 of the form shown in Fig. 3. Pipe 82, in this form, is in communication with chamber 98 and it will be evident that when the spill accompanying capacity operation of the injector occurs it will lift the valve head 90 from its seat 92 sufliciently to permit flow of the spill to chamber 98 and pipe 82. Flow from the overflow chamber 46 to the outlet passage 52 is prevented by engagement of the flange 94 with the surface 96 until breaking of the injector and the subsequent complete failure of delivery pressure permits the valve head 80 to be lifted so let the flange 94 is out of contact with the surface 96.

In Fig. 5 a variation of the arrangement just described is shown in which the valve head I00 is of the piston type having a lower annular valve face I02 adapted to engage a suitable valve seat and having a piston portion I04 engaging a suitable cylindrical slot I06 in which is located an annular recess forming a chamber I08 with-which pipe 82 is in communication. In this form it will be clear that the spill accompanying capacity operation will flow to chamber I08 and that breaking of the injector, resulting in failure of delivery pressure, will permit the valve head I00 tomove upwardly so that the piston portion thereof is out of engagement with the cylindrical wall which forms, in effect, the secondary valve seat.

In the arrangement illustrated in Fig. 6, two separate and independent valve heads arranged in series with respect to flow of water from the overflow chamber are employed, both of these valve heads being loaded directly by delivery pressure. Referring to the figure, the valve head IIO engaging a seat H2 at the outlet of the chamber 46 provides the primary overflow valve and valve head II4 engaging a seat II6 provides the secondary overflow valve. Valve stems H8 and I20 extending upwardly from valve heads H0 and H4 respectively, are engaged by the ends of a lever I22 which is in turn pivoted to the free end of lever 68, the opposite end of which is connected to the plunger I2, which is subjected to delivery pressure. Pipe 82, leading to the cab of the locomotive, is connected to the chamber I24, which is provided between the valve seats H2 and H6. The operation of this embodiment of the invention will be largely obvious from the drawings. When the injector operates at capacity, the spill accompanying such operation will slightly lift the valve head IIIJ against the force exerted by delivery pressure, the lever I22 pivoting about the upper end of the valve stem I20 as a fixed pivot, the resulting leakage in the chamber I24 causing a stream of water to flow upwardly through pipe 82 to the open discharge in the'locomotive cab. If and when the injector breaks, failure of delivery pressure on plunger I2 permits both of the valve heads to open and allows substantially free flow to pipe 34.

In all of the arrangements hereinbefore described, the overflow valve means comprises, in effect, two valves serially arranged with respect to the direction of flow of overflow from the in- Liector, with a chamber between the two valves from which a connection leads to the locomotive cab for conducting thereto the spill which leaks to this intermediate chamber.

In the arrangement shown in Fig. 7 the overflow valve means comprises two valve heads arranged in parallel with respect to the line of flow of the overflow fluid. In this arrangement the valve head corresponding to the secondary valve of the previously described embodiments is in the form of the usual conventional type of single seated overflow valve, and is indicated at I26 in the figure. The stem of this valve is contacted by the free end of lever 68 to seat the valve under the influence of delivery pressure acting on the plunger 12 and opening of this valve upon failure of delivery pressure provides for free overflow to the pipe 34. The valve corresponding in function to the primary valve of the arrangements previously described is provided by a valve head I28 located in a separate casing I30, which may be located either adjacent to the injector or in the cab adjacent to the open discharge end 84 of the pipe 82. Valve head I28 is adapted to engage a seat I32 in the lower part of casing I and the space below this seat is connected by pipe I34 to the overflow chamber 46 of the injector. The stem I34 of the valve I28 has attached thereto a bellows diaphragm I36 which, together with the upper portion of the casing I30, forms a pressure chamber I38. Chamber I38 is placed in communication with the delivery chamber 48 of the injector by means of the connection I 40. It will be evident that in this arrangement both the valve heads I26 and I28, are loaded, although independently, by delivery pressure, and both are subjected to the pressure that may exist in chamber 46 of the injector. If the injector is operating at capacity the accompanying spill will cause valve head I28 to be lifted slightly from its seat against delivery pressure. This may or may not be accompanied by a slight lifting from its seat of the valve head I26, since the relative opening of the two valves will depend upon the relation'with respect to the respective valve heads of the areas of the elements subjected to delivery pressure and also on the relative lengths of the two-arms of the lever 68. Preferably the area of the diaphragm I36 which is subjected to delivery pressure is such that valve head I28 will lift with a slightly lower pressure in the overflow chamber than is required to lift valve head I26. This arrangement insures flow of all or a major portion of the spill accompanying capacity operation through the pipe 82 to provide the desired indication of the condition of injector operation.

From the foregoing description it will be evident that the invention may be applied in many different ways, and it will further be evident that a signal provided by the spill accompanying capacity operation of the injector may be of a kind different from that illustrated. For reasons of simplicity and absolute reliability, I prefer to employ as a signal or indication the open flow of the spill at a prominent place in the cab adjacent tothe injector controls, but it will be evident that this flow can be utilized in other ways to provide other forms of either visual or aural signals.

What I claim is:

1. In injector apparatus for a locomotive having an operators cab, an injector having a main overflow passage; means for causing spill which accompanies capacity operation of the injector to flow through a passage other than said main overflow passage, and means providing a signal located in said cab and operable upon flow of such spill to indicate capacity operation of the injector.

2. In an injector having an overflow chamber and a mainoverflow passage leading from said chamber, valve means for controlling overflow from said chamber comprising two valves se rially arranged in the path of flow from said chamber through said passage, and an auxiliary overflow passage communicating with the space between said valves.

3. In an injector having an overflow chamber and a main overflow passage, valve means for controlling overflow fromsaid chamber comcontrolling overflow from said chamber comprising a primary valve and a secondary valve arranged in the order named in the path of flow from said chamber through said passage, said valves having independently movable valve heads, means for closing both of said valves under the influence of delivery pressure, and an auxiliary overflow passage communicating with the space between said valves.

5. In an injector having an overflow chamber and a main overflow passage, valve means for controlling overflow from said chamber comprising a primary valve and a secondary valve arranged in the order named in the path of flow from said chamber through said passage, said valves having independently movable valve heads, means for loading the primary valve head to seat it, spring means for seating the secondary valve head when the primary valve head is seated, and an auxiliary overflow passage communicating with the space between said valves.

6. In an injector having an overflow chamber and a main overflow passage, valve means for controlling overflow from said chamber comprising a single valve head having spaced valve faces adapted to cooperate with spaced seats to provide two spaced valves serially arranged with respect to flow from said chamber through said passages, the valve first in the path of flow being adapted to open prior to the opening of the second valve as the valve head moves away from closed position, and an auxiliary overflow passage communicating with the space between said valves.

7. In an injector having an overflow chamber and a main overflow passage, valve means for controlling overflow from said chamber comprising a single valve head having spaced valve faces adapted to cooperate with spaced seats to provide two spaced valves serially arranged with respect to flow from said chamber through said passages, the valve first in the path of flow being adapted to open prior to the opening of the second valve as the valve head moves away from closed position, means for loading said valve head due to delivery pressure, and an auxiliary overflow passage communicating with the space between said valves.

8. The combination with an injector having an overflow chamber, a main overflow passage and a main overflow valve for controlling flow through said passage, of means for loading said overflow valve due to delivery pressure, an auxiliary overflow passage in direct communication with said overflow chamber, a valve for controlling flow through said auxiliary overflow passage independently of flow through said main overflow passage, and separate means for loading the second-mentioned valve due to delivery pressure.

9. The combination with an injector having an overflow chamber, a main overflow passage and a main overflow valve for controlling flow through said passage, of means for loading said overflow valve due to delivery pressure, an auxiliary overflow passage in direct communication with said overflow chamber, said passage having an outlet placed to provide a visual indication of flow through said passage, a valve for controlling flow through said auxiliary overflow passage independently of flow through said main overflow passage, and separate means for loading the second mentioned valve due to delivery pressure, the last mentioned means being adjusted to provide for opening of the second mentioned valve with a lower value of overflow pressure than that required to effect full opening of the main overflow valve.

10. The combination with an injector having.

a main overflow passage providing a first path for flow of spill from the injector, of an auxiliary overflow passage providing a second path for flow of spill from the injector separate from said first path and valve means for both passages loaded to cause spill which accompanies capacity operation of the injector to flow through said auxiliary overflow passage.

11. In injector apparatus, means providing a main overflow passage for conducting spill from the injector, means providing an auxiliary overflow passage separate from said main passage for conducting spill from the injector and differentially loaded valve means adapted to be closed under the influence of delivery pressure for controlling flow through said passages, said valve means being constructed and arranged to direct spill which accompanies capacity operation of the injector through said auxiliary overflow passage while the injector is operating and delivery pressure is present and to open to permit flow through both of said passages upon failure of delivery pressure.

12. In injector apparatus, means providing a main overflow passage for conducting spill from the injector and an auxiliary overflow passage separate from said main passage for conducting spill from the injector, valve means comprising a valve for controlling flow through the main overflow passage and a valve for controlling flow through the auxiliary overflow passage and means for closing said valves under the influence of delivery pressure arranged to permit opening of the valve controlling flow through the auxiliary overflow passage while the valve controlling flow through the main overflow passage is closed.

13. In injector apparatus having remote control for the injector, an injector having a main overflow passage for conducting spill from the injector and means for causing spill which accompanies capacity operation of the injector to flow through a passage other than said main overflow passage, the second mentioned passage having an open discharge end located in the vicinity of the place of remote control of the injector for providing a visual signal indicating capacity operation of the injector.

14. In injector apparatus for a locomotive having an operators cab, an injector having a main overflow passage and means for causing spill which accompanies capacity operation of the injector to flow through a passage other than said main overflow passage, the second mentioned passage having an open discharge end located in said cab to provide a visual signal in the cab for indicating capacity operation of the injector.

JOSEPH F. GRIFFIN. 

